Joyce Hardin Garrard wanted to punish her granddaughter, Savannah, for having lied about eating sweets.
But the punishment ended up being so extreme that it led to the little girl’s death.
According to Garrard’s neighbours, the 50-year-old forced her 9-year-old granddaughter to run for three hours straight, sometimes carrying firewood.
Speaking at the trial, eyewitness Chad Jacobs explained: "Joyce and Savannah were in the yard, and Joyce was telling Savannah to keep running.”
He went on to reveal that, whenever the little girl stopped to catch her breath - or even to vomit, her grandmother forced her to continue.
"She was just saying, 'Keep running, I didn't tell you to stop’” he said, according to The Washington Post.
The young schoolgirl eventually collapsed and vomited, before suffering a seizure.
She was rushed to hospital but died three days later. Experts said she died of prolonged physical exertion.
Despite insisting that she meant the child no harm, Garrard has been found guilty of capital murder and Judge William Thornton (who took to Twitter to reveal the outcome of the trial) sentenced to life in prison - with no parole.
She could have faced the death penalty; however her lawyers insisted that a life in prison would be a far more suitable punishment.
“The worst punishment you could give is to send her to the penitentiary as the grandmother who ran her grandchild to death,” they said.